Compression apparatus

ABSTRACT

A compression apparatus in the present invention includes a compressor including a cylinder for compressing a gas, a gas cooler for cooling the gas compressed in the cylinder, and a circulation passage for guiding the gas compressed in the cylinder into the gas cooler. The gas cooler is diffusion bonded to the cylinder. In order to reduce the size of the compression apparatus, the circulation passage extends through an area in which the gas cooler and the cylinder face each other. At least areas surrounding the area are diffusion bonded.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to compression apparatuses for compressing a gas.

2. Description of the Related Art

In recent years, hydrogen stations for supplying hydrogen gas to fuel-cell vehicles have been proposed. In hydrogen stations, a compression apparatus for supplying hydrogen gas in a compressed state is used to efficiently charge fuel-cell vehicles with hydrogen gas. The compression apparatus includes a compressor for compressing hydrogen gas, and a gas cooler for cooling hydrogen gas that is raised in temperature by being compressed by the compressor. For the gas cooler, use of a plate-type heat exchanger as described, for example, in JP 2000-283668 A has been proposed.

A plate-type heat exchanger includes a laminated body in which a large number of plates are stacked in layers. Between the stacked plates, flow channels for circulating fluids are individually formed. In the heat exchanger, heat exchange is performed between fluids flowing through their respective flow channels that are adjacent to each other in the plate stacking direction.

SUMMARY OF THE INVENTION

The above-described compression apparatus requires a large number of pipes to connect the compressor and the gas cooler, and thus requires the securement of a large installation space.

The present invention has been made to solve the above problem, and its object is to reduce the size of compression apparatuses.

In order to achieve the above object, a compression apparatus according to the present invention includes a compressor including a cylinder for compressing a gas, a heat exchanger for cooling the gas compressed in the cylinder, and a circulation passage for guiding the gas compressed in the cylinder into the heat exchanger, in which the heat exchanger is solid-phase bonded to the cylinder, the circulation passage extends through an area in which the heat exchanger and the cylinder face each other, and the area is surrounded by a surface at which the heat exchanger and the cylinder are solid-phase bonded.

In the present invention, the heat exchanger is solid-phase bonded to the cylinder. The circulation passage extends through an area in which the heat exchanger and the cylinder face each other, and the area is surrounded by a surface at which the heat exchanger and the cylinder are solid-phase bonded. Therefore, installation space for piping to connect the cylinder and the heat exchanger can be omitted, and the compression apparatus can be reduced in size. Further, piping can be omitted, which also contributes to a reduction in the number of components. Moreover, since the heat exchanger and the cylinder are in close contact by solid-phase bonding, the possibility of gas leakage can be reduced when a high-pressure gas discharged from the compressor flows through the circulation passage.

Here, the solid-phase bonding may be diffusion bonding. In this aspect, leakage of a high-pressure gas discharged from the compressor can be reduced more securely.

The circulation passage may extend through a flat surface at which the heat exchanger and the cylinder are solid-phase bonded. In this aspect, one surface of the cylinder facing the heat exchanger and one surface of the heat exchanger facing the cylinder contact each other on the entire surfaces. These surfaces facing each other are solid-phase bonded. This allows the surfaces to be bonded to be pressurized evenly during solid-phase bonding. Thus, the possibility of gas leakage can be reduced more securely.

The heat exchanger may have a structure in which a plurality of plates are stacked in layers so that cooling flow channels through which a cooling fluid for cooling the gas flows and gas flow channels through which the gas flows are formed alternately. In this case, a plate of the plurality of plates disposed at the end on the cylinder side may be solid-phase bonded to the cylinder. In this aspect, good efficiency of cooling the gas by the cooling fluid can be achieved. Further, the heat exchanger can be easily mounted to the compressor.

In this aspect, the plates adjacent to each other may be solid-phase bonded. In this aspect, since the adjacent plates are solid-phase bonded, the possibility of leakage of a gas or a cooling fluid from between the plates can be reduced.

According to the present invention, compression apparatuses can be reduced in size.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram illustrating a configuration of a compression apparatus (with a recovery header removed) according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the compression apparatus taken in the position of arrows II-II in FIG. 1.

FIG. 3 is a cross-sectional view of the compression apparatus taken in the position of arrows III-III in FIG. 1.

FIG. 4 is a plan view of a hydrogen gas plate constituting a part of a gas cooler provided in the compression apparatus.

FIG. 5 is a plan view of a cooling water plate constituting a part of the gas cooler.

FIG. 6 is a diagram corresponding to FIG. 1 in another embodiment of the present invention.

FIG. 7 is a diagram corresponding to FIG. 2 in another embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

A compression apparatus according to an embodiment of the present invention is a compression apparatus used, for example, in a hydrogen station for supplying hydrogen to fuel-cell vehicles.

As shown in FIGS. 1 to 3, the compression apparatus according to this embodiment includes a compressor 2 for compressing hydrogen gas, and a gas cooler 4 for cooling hydrogen gas after being compressed by the compressor 2. The gas cooler 4 is a microchannel heat exchanger.

The compressor 2 is a reciprocating compressor, and includes a compression section 16 including a cylinder 5 and a piston 7, and a drive mechanism for driving the piston 7. The drive mechanism includes a crankcase 6, a crankshaft 8, a drive section not shown, a cross guide 10, a crosshead 12, and a connecting rod 14.

In the crankcase 6, the crankshaft 8 is provided rotatably around a horizontal axis. The drive section not shown is connected to the crankshaft 8, and transmits power to the crankshaft 8 to rotate the crankshaft 8.

The cross guide 10 is a tubular member continuously provided to the crankcase 6. In the cross guide 10, the crosshead 12 is housed reciprocatably in an axial direction of the cross guide 10. The connecting rod 14 connects the crankshaft 8 and the crosshead 12, and converts the rotary motion of the crankshaft 8 into a linear reciprocating motion for transmission to the crosshead 12.

The compression section 16 is constituted by a multistage compression mechanism, and includes a first compression section 61 for performing first-stage compression of hydrogen gas, and a second compression section 62 for performing second-stage compression of hydrogen gas. The cylinder 5 has a first cylinder section 63 included in the first compression section 61 and a second cylinder section 66 included in the second compression section 62. The piston 7 has a first piston 64 included in the first compression section 61 and a second piston 67 included in the second compression section 62.

The first cylinder section 63 is formed in a tubular shape. One end of the first cylinder section 63 is coupled to an axial end of the cross guide 10.

The interior space of the first cylinder section 63 functions as a first cylinder chamber 63 a. In the first cylinder chamber 63 a, the first piston 64 is reciprocatably housed. The first piston 64 is connected to the crosshead 12 by the piston rod 24. Thus, the first piston 64 moves with the crosshead 12 in an integrated manner.

The second cylinder section 66 is formed integrally with the first cylinder section 63. The second cylinder section 66 is formed with a bottomed hole that communicates with the first cylinder chamber 63 a and extends in an axial direction of the second cylinder section 66. An axial end of the hole is closed by an end wall 66 c of the second cylinder section 66. The hole functions as a second cylinder chamber 66 a. The second cylinder chamber 66 a reciprocatably houses the second piston 67.

The first cylinder chamber 63 a and the second cylinder chamber 66 a are spaces both in circular cross-sectional shapes. The second cylinder chamber 66 a is smaller in diameter than the first cylinder chamber 63 a, and is formed coaxially with the first cylinder chamber 63 a. In the first cylinder chamber 63 a, a space between the first piston 64 and a partition wall 25 on the piston rod 24 side functions as a first compression chamber 63 b for compressing hydrogen gas.

The second piston 67 is connected to an end of the first piston 64 opposite to an end to which the piston rod 24 is connected, and extends from the first piston 64 to the side opposite to the piston rod 24. The first piston 64 and the second piston 67 are formed both in cylindrical shapes. The second piston 67 is smaller in diameter than the first piston 64.

In the second cylinder chamber 66 a, a space between the second piston 67 and the end wall 66 c of the second cylinder section 66 functions as a second compression chamber 66 b in which hydrogen gas compressed in the first compression chamber 63 b is further compressed. That is, a compression chamber 16 a of the compression section 16 includes the first compression chamber 63 b and the second compression chamber 66 b.

FIG. 2 is a cross-sectional view of the compression apparatus taken in the position of arrows II-II in FIG. 1. The first cylinder section 63 includes a first inlet valve chamber 69 a, a first inlet side communication passage 70 a, a first inlet passage 71, a first delivery valve chamber 69 b, a first delivery side communication passage 70 b, and a first delivery passage 72.

The first inlet valve chamber 69 a and the first delivery valve chamber 69 b are located on the opposite sides of the first compression chamber 63 b. The first inlet valve chamber 69 a and the first delivery valve chamber 69 b individually extend in a direction perpendicular to the moving direction of the first and second pistons 64 and 67 in a horizontal plane.

In the first inlet valve chamber 69 a, a first inlet valve 74 a is housed and fixed by a first inlet valve fixing flange 75 a. The first inlet side communication passage 70 a is a passage for connecting the first compression chamber 63 b and the first inlet valve chamber 69 a. In the first delivery valve chamber 69 b, a first delivery valve 74 b is housed and fixed by a first delivery valve fixing flange 75 b. The first delivery side communication passage 70 b is a passage for connecting the first compression chamber 63 b and the first delivery valve chamber 69 b.

The first inlet passage 71 is disposed on the upper side of the first inlet valve chamber 69 a, and extends downward from the upper surface of the first cylinder section 63 to be connected to the first inlet valve chamber 69 a. To the upper end of the first inlet passage 71, a supply pipe 76 is connected to supply hydrogen gas from a supply source not shown therethrough.

The first delivery passage 72 extends from the first delivery valve chamber 69 b to the lower surface of the first cylinder section 63. The first delivery passage 72 has a first delivery passage opening 72 a opening in the lower surface of the first cylinder section 63.

FIG. 3 is a cross-sectional view of the compression apparatus taken in the position of arrows III-III in FIG. 1. The lower surface of the second cylinder section 66 and the lower surface of the first cylinder section 63 are formed flush in a planar shape. That is, in the compressor 2, an area opposite to the gas cooler 4 is formed by a flat surface.

The second cylinder section 66 includes a second inlet valve chamber 78 a, a second inlet side communication passage 79 a, a second inlet passage 80, a second delivery valve chamber 78 b, a second delivery side communication passage 79 b, and a second delivery passage 81.

The second inlet valve chamber 78 a and the second delivery valve chamber 78 b are located on the opposite sides of the second compression chamber 66 b. The second inlet valve chamber 78 a and the second delivery valve chamber 78 b individually extend in a direction perpendicular to the moving direction in a horizontal plane. In the second inlet valve chamber 78 a, a second inlet valve 83 a is housed and fixed by a second inlet valve fixing flange 84 a. The second inlet side communication passage 79 a is a passage for connecting the second compression chamber 66 b and the second inlet valve chamber 78 a. In the second delivery valve chamber 78 b, a second delivery valve 83 b is housed and fixed by a second delivery valve fixing flange 84 b. The second delivery side communication passage 79 b is a passage for connecting the second compression chamber 66 b and the second delivery valve chamber 78 b.

The second inlet passage 80 is disposed on the lower side of the second inlet valve chamber 78 a, and extends upward from the lower surface of the second cylinder section 66 to be connected to the second inlet valve chamber 78 a. The second inlet passage 80 has a second inlet passage opening 80 a opening in the lower surface of the second cylinder section 66.

The second delivery passage 81 is disposed on the upper side of the second delivery valve chamber 78 b, and extends downward from the upper surface of the second cylinder section 66. To the upper end of the second delivery passage 81, a communicating pipe 85 is connected.

The gas cooler 4 is a heat exchanger for cooling hydrogen gas compressed in the compressor 2 by water as a cooling fluid, and includes a main body 38, a supply header 42 (see FIG. 3), and a recovery header 44 (see FIG. 3).

The main body 38 is a laminated body in which gas plates 46 and water plates 48 are stacked in layers between a pair of end plates 50 and 50. In this embodiment, a partition plate 88 is interposed in a middle position of the main body 38. The main body 38 is divided into two parts by the partition plate 88.

Specifically, the main body 38 includes a first cooling section 86 that is a heat exchanger for cooling hydrogen gas after first-stage compression, and a second cooling section 87 that is a heat exchanger for cooling hydrogen gas after second-stage compression. The interior of the main body 38 is partitioned into the first cooling section 86 and the second cooling section 87 by the partition plate 88.

The first cooling section 86 is disposed on the compressor 2 side with respect to the partition plate 88, and the second cooling section 87 is disposed opposite to the compressor 2 with respect to the partition plate 88.

The first cooling section 86 and the second cooling section 87 each include the gas plates 46 and the water plates 48. The gas plates 46 and the water plates 48 are disposed alternately.

As shown in FIG. 4, each gas plate 46 is a rectangular plate formed from stainless steel. Each gas plate 46 has an inflow passage through hole 46 d and a discharge passage through hole 46 e. Further, a plurality of gas channel grooves 46 a, a distribution section groove 46 b, and a recovery section groove 46 c are formed in one surface of each gas plate 46. The distribution section groove 46 b is connected to the inflow passage through hole 46 d, and the recovery section groove 46 c is connected to the discharge passage through hole 46 e. When the gas plates 46 and the water plates 48 are stacked on each other, gas flow channels 54 are formed by the gas channel grooves 46 a and the water plates 48.

As shown in FIG. 5, like the gas plates 46, each water plate 48 is a rectangular plate formed from stainless steel. Each water plate 48 has an inflow passage through hole 48 b and a discharge passage through hole 48 c. A plurality of water channel grooves 48 a is formed in one plate surface of each water plate 48. When the water plates 48 and the gas plates 46 are stacked on each other, cooling water flow channels 57 are formed by the water channel grooves 48 a and the gas plates 46.

The end plates 50 are each a rectangular plate formed from stainless steel. The end plate 50 on the first cooling section 86 side is diffusion bonded to the lower surface of the cylinder 5 (the first cylinder section 63 and the second cylinder section 66) of the compressor 2, and is in close contact with the lower surface. Specifically, being kept in close contact with each other, the cylinder 5 and the end plate 50 are pressurized under a temperature condition lower than or equal to the melting points of their base materials to an extent that it causes minimum plastic deformation, and bonded utilizing the diffusion of atoms occurring between the bonded surfaces. The upper surface of the end plate 50 is a flat surface and constitutes an area opposite to the cylinder 5 of the compressor 2.

An inflow passage through hole 50 b and a discharge passage through hole 50 d are formed in the end plate 50 (see FIGS. 2 and 3). Hydrogen gas discharged from the compressor 2 and introduced into the gas cooler 4 passes through the inflow passage through hole 50 b. Hydrogen gas discharged from the gas cooler 4 passes through the discharge passage through hole 50 d.

The gas plates 46 in the first cooling section 86 are disposed opposite in orientation to those in the second cooling section 87, and also the end plates 50 a and the water plates 48 are disposed opposite in orientation likewise. That is, the positional relationship between the distribution section grooves 46 b and the recovery section grooves 46 c of the gas plates 46 in the first cooling section 86 is opposite to that in the second cooling section 87, and also the positional relationship between the inflow passage through holes 46 d and the discharge passage through holes 46 e in the first cooling section 86 is opposite to that in the second cooling section 87. For the end plates 50 a and the water plates 48, the positional relationship between the inflow passage through holes 48 b and 50 b and the discharge passage through holes 48 c and 50 d in the first cooling section 86 is opposite to that in the second cooling section 87.

Adjacent plates of the gas plates 46, the water plates 48, the end plates 50, and the partition plate 88 are bonded to each other by diffusion bonding.

In the first cooling section 86, the inflow passage through holes 46 d, 48 b, and 50 b of the respective plates communicate with each other, thereby forming a first gas inflow passage 52 a extending in the plate stacking direction. An opening 52 c on the inflow side of the first gas inflow passage 52 a communicates with the first delivery passage opening 72 a of the first delivery passage 72. Thus, hydrogen gas compressed in the first compression section 61 and flowing through the first delivery side communication passage 70 b and the first delivery passage 72 flows into the first gas inflow passage 52 a. The hydrogen gas flowing through the first gas inflow passage 52 a is introduced into the gas flow channels 54 in the first cooling section 86. Accordingly, hydrogen gas is allowed to flow from the compressor 2 into the gas cooler 4 without flowing through any pipe.

In the first cooling section 86, the discharge passage through holes 46 e, 48 c, and 50 d communicate with each other, thereby forming a first gas discharge passage 53 a extending in the plate stacking direction. An opening 53 c on the discharge side of the first gas discharge passage 53 a communicates with the second inlet passage opening 80 a of the second inlet passage 80. Thus, hydrogen gas cooled by cooling water in the first cooling section 86 passes through the opening 53 c of the first gas discharge passage 53 a. The hydrogen gas is discharged to the second compression section 62.

In the second cooling section 87, the inflow passage through holes 46 d, 48 b, and 50 b of the respective plates communicate with each other, thereby forming a second gas inflow passage 52 b extending in the plate stacking direction. The second gas inflow passage 52 b guides hydrogen gas compressed in the second compression section 62 and introduced into the second cooling section 87 through the communicating pipe 85 into the gas flow channels 54 in the second cooling section 87.

In the second cooling section 87, the discharge passage through holes 46 e, 48 c, and 50 d communicate with each other, thereby forming a second gas discharge passage 53 b extending in the plate stacking direction. The second gas discharge passage 53 b discharges hydrogen gas cooled by cooling water in the second cooling section 87 to a discharge pipe 89.

As shown in FIG. 3, to one side of the right and left sides of the main body 38, the supply header 42 to which a cooling water supply pipe 58 is connected is attached, and to the other side, the recovery header 44 to which a cooling water recovery pipe 59 is connected is attached. In the gas cooler 4, cooling water flows from the cooling water supply pipe 58 through the supply header 42, the cooling water channels 57 (see FIG. 5), and the recovery header 44 to the cooling water recovery pipe 59.

When the compression apparatus is driven, hydrogen gas is taken in from the first inlet passage 71 into the first compression chamber 63 b via the first inlet valve 74 a (see FIG. 2). In the first compression chamber 63 b, the hydrogen gas is compressed by the first piston 64 and discharged from the first cylinder section 63 through the first delivery side communication passage 70 b and the first delivery passage 72. The hydrogen gas flows into the first cooling section 86 of the gas cooler 4 through the first delivery passage opening 72 a. That is, the first delivery side communication passage 70 b and the first delivery passage 72 function as a circulation passage 77 for guiding hydrogen gas compressed in the cylinder 5 to the heat exchanger.

In the first cooling section 86, the hydrogen gas flows from the first gas inflow passage 52 a into the gas flow channels 54 (FIG. 4), and is cooled by exchanging heat with cooling water flowing through the cooling water flow channels 57 (FIG. 5). The cooled hydrogen gas is discharged from the first cooling section 86 to the second compression chamber 66 b via the first gas discharge passage 53 a. In the second compression chamber 66 b, the hydrogen gas is further compressed by the second piston 67.

The hydrogen gas compressed in the second compression chamber 66 b is discharged through the second delivery passage 81 to the communicating pipe 85. The hydrogen gas discharged to the communicating pipe 85 flows into the second gas inflow passage 52 b of the second cooling section 87. After cooled in the second cooling section 87, the hydrogen gas flows into the second gas discharge passage 53 b and is discharged to the discharge pipe 89.

In the compression apparatus according to this embodiment, since the gas cooler 4 is directly fixed to the compressor 2, piping between the compressor 2 and the gas cooler 4 can be omitted. As a result, space for piping installation becomes unnecessary, and thus the compression apparatus can be reduced in size. Further, the number of pipes can be reduced, which also contributes to a reduction in the number of components. Moreover, since the gas cooler 4 and the cylinder 5 are in close contact by diffusion bonding, without the provision of a sealing member for sealing against hydrogen gas, the possibility of gas leakage can be reduced when a high-pressure gas discharged from the compressor 2 flows through the circulation passage.

In this embodiment, one surface of the cylinder 5 facing the gas cooler 4 (or the first cooling section 86) and one surface of the gas cooler 4 (or the first cooling section 86) facing the cylinder 5 contact each other on the entire surfaces. These surfaces facing each other are diffusion bonded. This allows the surfaces to be bonded to be pressurized evenly during diffusion bonding. Thus, the possibility of gas leakage can be reduced more securely.

In this embodiment, since the gas cooler 4 consists of the plurality of plates 46 and 48 stacked in layers, good efficiency of cooling hydrogen gas by cooling water can be achieved. Further, the gas cooler 4 can be easily mounted to the compressor 2.

In this embodiment, in the gas cooler 4, since the adjacent plates 46 and 48 are diffusion bonded to each other, the possibility of leakage of hydrogen gas or cooling water from between the plates 46 and 48 can be reduced.

It should be considered that the embodiment disclosed now is illustrative in all respects and is not limiting. The scope of the present invention is indicated not by the description of the above-described embodiment but by the scope of claims, and also includes all modifications within a meaning and scope equivalent to the scope of claims.

For example, as the gas cooler 4, other various plate-type heat exchangers such as plate-fin type heat exchangers may be used. A plate-fin heat exchanger is different from a microchannel heat exchanger in the manner in which a groove shape is machined and the manner in which stacked layers are bonded to each other, but has a structure functionally similar to that of the microchannel heat exchanger. A tube-type heat exchanger may also be used as the heat exchanger.

In the above-described embodiment, the compressor 2 is configured to include the compression section 16 composed of the plurality of compression sections 61 and 62, which is not limiting. Alternatively, as shown in FIG. 6, for example, the compressor 2 may be configured to include a single-stage compression-type compression section 16, or may include a compression section with three or more stages (not shown). In a compression apparatus including the single compression section 16 as shown in FIG. 6, the interior of a cylinder 5 is divided into two spaces by a piston 7. The space opposite to a piston rod 24 functions as a compression chamber 16 a. A delivery passage 18 communicating with the compression chamber 16 a is provided at the cylinder 5. An opening 18 a of the delivery passage 18 is formed in the lower surface of the cylinder 5. The delivery passage 18 communicates with gas flow channels 54 of a gas cooler 4. The gas cooler 4 is not configured to be divided into a first cooling section 86 and a second cooling section 87, and thus a partition plate 88 is not provided. Thus, hydrogen gas introduced from the delivery passage 18 into the gas flow channels 54 is cooled by cooling water in the gas flow channels 54, and then discharged from a discharge pipe 89 of the gas cooler 4.

Further, application may be made to a compression apparatus in which a cross guide 10 and a cylinder 5 are coupled in a vertical direction so that the moving direction of a piston 7 is a vertical direction, and a gas cooler 4 is mounted to a side of the cylinder 5.

The gas flow channels 54 may alternatively be formed in a meandering shape on the plate surface of each gas plate 46. The cooling water flow channels 57 may alternatively be formed in a meandering shape on the plate surface of the each water plate 48. This configuration can increase the surface areas of the gas flow channels 54 and the cooling water flow channels 57, allowing for more effective cooling of hydrogen gas. The compression apparatus in the above-described embodiments may be used for a gas lighter than air such as helium gas or natural gas other than hydrogen gas, and may be used for compression of a gas such as carbon dioxide.

In the above-described embodiments, the upper surface of the gas cooler 4 and the lower surface of the cylinder 5 of the compressor 2 are individually formed flat, and are configured to be solid-phase bonded over the entire surfaces. However, this is not limiting. For example, as shown in FIG. 7, the lower surface of a cylinder 5 may be configured such that it partially has an area that is not flat, and at a recessed area 5 a, the lower surface of the cylinder 5 is not in close contact with the upper surface of a gas cooler 4. That is, the cylinder 5 may be configured such that an area in which a first delivery passage 72 opens and an area in which a gas inflow passage 52 a opens in the gas cooler 4 are not diffusion bonded. However, also in this case, an area surrounding an opening 72 a of the first delivery passage 72 needs to be diffusion bonded to the gas cooler 4 at the lower surface of the cylinder 5.

The above-described embodiments have a structure in which the gas cooler 4 and the cylinder 5 are diffusion bonded, which is not limiting. For bonding between the gas cooler 4 and the cylinder 5, another solid-phase bonding such as explosive welding may be used. 

What is claimed is:
 1. A compression apparatus comprising: a compressor including a cylinder for compressing a gas; a heat exchanger for cooling the gas compressed in the cylinder; and a circulation passage for guiding the gas compressed in the cylinder into the heat exchanger, wherein: the heat exchanger is solid-phase bonded to the cylinder; the circulation passage extends through an area in which the heat exchanger and the cylinder face each other; and the area is surrounded by a surface at which the heat exchanger and the cylinder are solid-phase bonded.
 2. The compression apparatus according to claim 1, wherein: the solid phase bonding is diffusion bonding.
 3. The compression apparatus according to claim 1, wherein: the circulation passage extends through a flat surface at which the heat exchanger and the cylinder are solid-phase bonded.
 4. The compression apparatus according to claim 1, wherein: the heat exchanger has a structure in which a plurality of plates are stacked in layers so that cooling flow channels through which a cooling fluid for cooling the gas flows and gas flow channels through which the gas flows are formed alternately; and a plate of the plurality of plates disposed at the end on the cylinder side is solid-phase bonded to the cylinder.
 5. The compression apparatus according to claim 4, wherein: the plates adjacent to each other are solid-phase bonded. 